Insect repellents



Patented Aug. 21, 1951 INSECT REPELLENTS Paul D. Bartlett, Weston,

North Adams, Mass., States of America as r tary of the Army and Sidney D. Ross,

assignors to the United epresented by the Secre- No Drawing. Application January 7, 1949, Serial No. 69,831

8 Claims.

This invention relates to insect repellents.

We have found that the application of an ester of furylacrylic acid and an aliphatic alcohol having at least 4 carbon atoms, when applied to the human skin or a fabric, effectively repels insects, particularly Aedes aegZ/Pti and Anopheles quadrimaculatus.

The esters of furylacrylic acid contemplated in our invention have the structural formula O.CH:CH.CH:C.CH:CPCOOR wherein R is the residue of an aliphatic alcohol having at least four carbon atoms.

Tests to measure the repellency of the abovementioned compounds against insects by skin application were conducted by smearing the compound on the arms of test personnel, who then thrust their arms into cages containing insects. The arms were exposed for 30-minute intervals at 3 minutes each until the first insect bite.

Tests to measure the repellency of fabrics impregnated with the above-mentioned compounds against insects were conducted by uniformly impregnating mercerized cotton hose with the compound at a rate equivalent to 3.3 gms. per sq. ft., drawing the dried hose over the arms of test personnel, who then thrust their covered arms into cages containing insects for 1 to 2 minutes.

Examples of aliphatic alcohols with at least 4 carbon atoms, whose esterification products with furylacrylic acid have insect-repellent properties, are, for instance, saturated compounds such as sec-butyl alcohol and amyl alcohol, unsaturated compounds such as methallyl alcohol, and alkoxy compounds such as cellosolve (2-ethoxy-ethanol).

The following table illustrates the results obtained by the above test methods against Aedes aegypti and Anopheles quadrimaculatus, as examples of insects against which the invention is applicable, by using compounds in accordance with the present invention.

Insect Repellency upon Application Insect Reto Skin pellency of Material i iffii Anopheles against i uadri- Aedes mnculatus Aegypti Mine. Mine. Sec-bartyl ester of iurylacrylic 188 62 over 5 days.

ac Am lcsteroiiurylacrylic acid. over 120 over days. Metl gllyl ester of iurylacrylic 198 38 Do.

ac Cellggolve ester of iurylacrylic 207 42 Do.

For ease of application, the furylacrylic acid esters contemplated by the present invention may be incorporated in a suitable inert liquid or solid carrier such as mineral oil, alcohol, petrolatum, etc. For facile and uniform fabric impregnation, they may be applied in an inert solvent, such as alcohol, ether, etc.

Havingthus fully described our invention, we claim:

1. An insect repellent fabric comprising fabric impregnated with an ester of furylacrylic acid and of an aliphatic alcohol having 4 carbon atoms in its molecule.

2. An insect-repellent fabric comprising fabric impregnated with the methallyl ester of furylacrylic acid.

3. An insect-repellent fabric comprising fabric impregnated. with the Cellosolve ester of fury]- acrylic acid.

4. An insect-repellent composition. comprising in an inert non-gaseous organic carrier an ester of furylacrylic acid and of a saturated aliphatic alcohol having 4 carbon atoms in its molecule.

5. An insect-repellent composition comprising the sec-butyl ester of furylacrylic acid in an inert non-gaseous organic carrier.

6. An insect-repellent composition comprising the methallyl ester of furylacrylic acid in an inert non-gaseous organic carrier.

7. An insect-repellentcomposition comprising the Cellosolve ester of furylacrylic acid in an inert non-gaseous organic carrier.

8. An insect-repellent composition comprising an ester of furylacrylic acid and of an aliphatic alcohol having four carbon atoms in its molecule in a non-gaseous inert organic carrier.

PAUL D. BARTLETT. SIDNEY D. ROSS.

REFERENCES CITED UNITED STATES PA'IEN is Name Date Jones et al 4.. May 7, 1946 OTHER REFERENCES Gilman et al.: Preparation of Some Perfumes, from 1929 Chemical Abstracts. vol. 23, page 3993.

OSRD Bimonthly Progress Report No. 24, Section 1, Period Ending June 30, 1945, particularly page 7, Orlando Nos. 0-5865, 0-5884. Publication date, August 1, 1947. I

OSRD Insect Control Committee Report No. 16, Interim Report No. 0-87, February 1, 1945, particularly pages 72, 74, Orlando Nos. 0-3301, 0-4246. Publication date, August 1, 1947.

Eddy et al.: Further tests Chemical Abstracts, vol. 41, 1947, pages 3575 and 3576.

Number 

4. AN INSECT-REPELLENT COMPOSITION COMPRISING IN AN INERT NON-GASEOUS ORGANIC CARRIER AN ESTER OF FURYLACRYLIC ACID AND OF A SATURATED ALIPHATIC ALCOHOL HAVING 4 CARBON ATOMS IN ITS MOLECULE. 